Several data processor designs offer floating-point calculations. A floating-point value consists of two pieces: (1) an exponent; and (2) a mantissa. It is common that each of the exponent and mantissa values are calculated separately and combined to create the final floating-point result.
One known microprocessor exponent calculation for floating-point divide and floating-point square root does not begin until the mantissa portion of the result has been calculated. Thus the execution time for these instructions is the sum of the calculation time of the mantissa plus the calculation time of the exponent (i.e., the exponent is serially calculated after the mantissa is calculated). This results in an overall inefficient and relatively long instruction execution time for floating point operations. This known microprocessor also uses multiple adders in its exponent calculation, which consumes a significant amount of integrated circuit die space and increases cost and design times.
Another known microprocessor also performs exponent calculations for floating-point divide. This calculation occurs in parallel to the mantissa calculation, but it does so using multiple exponent adder circuits. Therefore, this known microprocessor requires a larger surface area and cost in order to implement.